Hi, recently my 20" iMac has been showing some strange graphic problems when starting up, it doesn't happen all the time. Its hard to explain, what it looks like so I was able to capture a video of it on my iPhone, it happens near the end of the boot cycle; Here's a link to the video; http://www.twitvid.com/W2ERC I've tried clearing the PRAM etc and no luck. The iMac will be two years old this August, I don't have AppleCare. Do you think the video card is dying? Thanks, Chris.